There's been so much talk about the real identity of Charles DiLaurentis that sometimes the truth gets clouded among all of the fan theories. It was revealed in the Season 5 finale of Pretty Little Liars that Charles was one of the two young boys in the DiLaurentis home movies, which prompted fans (including myself) to assume that he must be Jason's twin. At first, I assumed that was the only logical explanation — until everyone associated with Pretty Little Liars gave fans reason to doubt that. According to a recent interview with Sasha Pieterse, Charles is a member of the DiLaurentis family, but she's careful to avoid confirming that he's Ali's brother and/or Jason's twin. Pieterse isn't the only one to avoid the sibling connection: the cast and crew have kept mostly silent on that matter, which leads me to wonder if maybe we're totally off base here. Could Charles be a cousin of the DiLaurentis family and not a sibling after all?
It's certainly a possibility. In fact, Charles being Ali's cousin might clear up some of the weirder elements of Charles as a villain. If Charles is related to the DiLaurentis family, but not to any of the Hastings, that opens up the possibility that perhaps someone connected to the Hastings girls really is A — like, say, Wren. If Charles was Jason's twin, that would mean that Charles is also Spencer and Melissa's brother, which automatically wipes anyone off the A suspect list who has ever so much as kissed the Hastings girls. (At least, I sincerely hope so?) That list could include Andrew, Wren, Toby, and any of the random love interests that popped into Spencer's life over the course of Season 5. Basically, we have way, way more options.
Then there's the theory that it's actually Jessica DiLaurentis, and not Jason, who has the secret twin. I always found the theory particularly far-fetched, but what if it's not? What if Jessica helped raise her incapacitated sister's child as her own, only to abandon him in his time of need — and created a far more monstrous Charles in the process? A secret nephew would be much easier to hide from the world than a secret son, which would explain why no one seems to have any clue who Charles is despite his age in the home videos. It would also explain why Jessica wanted to protect Charles, assuming he did hit her own daughter with the rock — she felt guilty for turning him into what he became.
As with everything on Pretty Little Liars, this is pure speculation — and until the Season 6A finale answers all of our questions about Charles, I'm going to keep on speculating.